Comprehensive Guide: How to Attach Propane to Outdoor Water Heater

Attaching propane to an outdoor water heater requires careful consideration of technical specifications and safety protocols. This comprehensive guide will walk you through the step-by-step process, ensuring your outdoor water heater is properly and safely connected to a propane source.

Assess Your Current Setup

Before you begin the installation process, it’s crucial to evaluate your existing outdoor water heater setup. Determine if your current venting system is compatible with a propane tankless water heater. If you only have a single vent, it may need to be modified to go through the roof, depending on the specific requirements of your water heater brand.

Choose the Right Propane Tank

how to attach propane to outdoor water heater

For a tankless hot water heater with a 3/4″ NPT propane input, a 40lb (10-gallon) propane bottle is a suitable choice if it’s placed right next to the water heater. This size tank will provide sufficient fuel capacity to meet your hot water demands without the need for frequent refills.

Install the Correct Regulator and Equipment

When connecting your propane tank to the outdoor water heater, it’s essential to use the proper regulator and equipment. Apply PTFE Thread Seal Tape to all connections, except for the hand-threaded Tank Connector. A Universal Kit typically includes the necessary tape, but it’s important to ensure it’s labeled as rated for the specific application.

The required gas supply pressure for the Rinnai V65EP model, for example, is 8.0 – 13.5 inches of water column (W.C.). Ensure that your regulator is capable of delivering the appropriate pressure range to your water heater.

Connect the Propane Tank to the Water Heater

For a Rheem Tankless Water Heater (Model # RTG-70XLP-1), you’ll need to connect the propane tank using a reducer and a second reducer to get the pressure down to the recommended level. Then, install the largest demand regulator recommended for RV use to ensure the proper gas flow and pressure.

Install Copper Lines and Fittings

Use three-quarter inch copper tubing from the tankless water heater and then connect it to the PEX (cross-linked polyethylene) piping using a Shark Bite fitting. This particular fitting will allow you to seamlessly connect the copper and PEX on either side. Be sure to follow the manufacturer’s instructions for proper installation and ensure all connections are secure.

Ensure Safety

Running liquefied petroleum (LP) gas on natural gas (NG) appliances can be extremely dangerous. If your friend has converted from NG to propane, the orifice at the burner and the gas valve itself must be changed. LP and NG valves have different ratings, with NG valves typically rated at around 3″ water column and LP at 10″ W.C.

Adding more water column (pressure) to an NG-rated gas valve at 3″ W.C. and transitioning it to LP at 10″ W.C. can be hazardous. To mitigate this risk, be sure to use a regulator to maintain the LP pressure at approximately 12″ W.C.

By following these steps and adhering to the technical specifications, you can successfully attach propane to your outdoor water heater. Remember, safety should always be your top priority when working with gas-powered appliances.